Replace cStringIO module with io as StringIO is now part of io module
Replace izip module with built in zip
Replace xrange with range as it was renamed.
Replace urlparse to urllib.parse as the module was moved there.
Replace unicode with str as str is now unicode. Don't know the best way of doing this.
Replace urlib2 with python's 3 built-in urllib
In python 3, maps returns an iterable object, and this breaks the current api. Calling list returns the expected value but might cause a performance issue.